In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction
Answer:
The density of the metal is 5200 kg/m³.
Explanation:
Given that,
Weight in air= 0.10400 N
Weight in water = 0.08400 N
We need to calculate the density of metal
Let
be the density of metal and
be the density of water is 1000kg/m³.
V is volume of solid.
The weight of metal in air is



.....(I)
The weight of metal in water is
Using buoyancy force


We know that,
....(I)
Put the value of
in equation (I)

Put the value of Vg in equation (II)



Hence, The density of the metal is 5200 kg/m³.
Answer:
Y = 78.13 x 10⁹ Pa = 78.13 GPa
Explanation:
First we will find the centripetal force acting on the wire as follows:
F = mv²/r
where,
F = Force = ?
m = mass of rock = 0.34 kg
v = speed = 19 m/s
r = length of wire
Therefore,
F = (0.34)(19)²/r
F = 122.74/r
now, we find cross-sectional area of wire:
A = πd²/4
where,
A = Area = ?
d = diameter of wire = 1 mm = 0.001 m
Therefore,
A = π(0.001)²/4
A = 7.85 x 10⁻⁷ m²
Now, we calculate the stress on wire:
Stress = F/A
Stress = (122.74/r)/(7.85 x 10⁻⁷)
Stress = 1.56 x 10⁸/r
Now, we calculate strain:
Strain = Δr/r
where,
Δr = stretch in length = 2 mm = 0.002 m
Therefore,
Strain = 0.002/r
now, for Young's modulus (Y):
Y = Stress/Strain
Y = (1.56 x 10⁸/r)/(0.002/r)
<u>Y = 78.13 x 10⁹ Pa = 78.13 GPa</u>
A is false, the conservation of energy states that energy can not be created or destroyed but is altered from one form to another